2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
27 #include "xfs_mount.h"
28 #include "xfs_da_format.h"
29 #include "xfs_da_btree.h"
30 #include "xfs_inode.h"
32 #include "xfs_dir2_priv.h"
33 #include "xfs_error.h"
34 #include "xfs_trace.h"
36 #include "xfs_trans.h"
37 #include "xfs_dinode.h"
40 * Directory file type support functions
42 static unsigned char xfs_dir3_filetype_table
[] = {
43 DT_UNKNOWN
, DT_REG
, DT_DIR
, DT_CHR
, DT_BLK
,
44 DT_FIFO
, DT_SOCK
, DT_LNK
, DT_WHT
,
52 if (!xfs_sb_version_hasftype(&mp
->m_sb
))
55 if (filetype
>= XFS_DIR3_FT_MAX
)
58 return xfs_dir3_filetype_table
[filetype
];
61 * @mode, if set, indicates that the type field needs to be set up.
62 * This uses the transformation from file mode to DT_* as defined in linux/fs.h
63 * for file type specification. This will be propagated into the directory
64 * structure if appropriate for the given operation and filesystem config.
66 const unsigned char xfs_mode_to_ftype
[S_IFMT
>> S_SHIFT
] = {
67 [0] = XFS_DIR3_FT_UNKNOWN
,
68 [S_IFREG
>> S_SHIFT
] = XFS_DIR3_FT_REG_FILE
,
69 [S_IFDIR
>> S_SHIFT
] = XFS_DIR3_FT_DIR
,
70 [S_IFCHR
>> S_SHIFT
] = XFS_DIR3_FT_CHRDEV
,
71 [S_IFBLK
>> S_SHIFT
] = XFS_DIR3_FT_BLKDEV
,
72 [S_IFIFO
>> S_SHIFT
] = XFS_DIR3_FT_FIFO
,
73 [S_IFSOCK
>> S_SHIFT
] = XFS_DIR3_FT_SOCK
,
74 [S_IFLNK
>> S_SHIFT
] = XFS_DIR3_FT_SYMLINK
,
79 xfs_inode_t
*dp
, /* incore directory inode */
80 struct dir_context
*ctx
)
82 int i
; /* shortform entry number */
83 xfs_mount_t
*mp
; /* filesystem mount point */
84 xfs_dir2_dataptr_t off
; /* current entry's offset */
85 xfs_dir2_sf_entry_t
*sfep
; /* shortform directory entry */
86 xfs_dir2_sf_hdr_t
*sfp
; /* shortform structure */
87 xfs_dir2_dataptr_t dot_offset
;
88 xfs_dir2_dataptr_t dotdot_offset
;
93 ASSERT(dp
->i_df
.if_flags
& XFS_IFINLINE
);
95 * Give up if the directory is way too short.
97 if (dp
->i_d
.di_size
< offsetof(xfs_dir2_sf_hdr_t
, parent
)) {
98 ASSERT(XFS_FORCED_SHUTDOWN(mp
));
99 return XFS_ERROR(EIO
);
102 ASSERT(dp
->i_df
.if_bytes
== dp
->i_d
.di_size
);
103 ASSERT(dp
->i_df
.if_u1
.if_data
!= NULL
);
105 sfp
= (xfs_dir2_sf_hdr_t
*)dp
->i_df
.if_u1
.if_data
;
107 ASSERT(dp
->i_d
.di_size
>= xfs_dir2_sf_hdr_size(sfp
->i8count
));
110 * If the block number in the offset is out of range, we're done.
112 if (xfs_dir2_dataptr_to_db(mp
, ctx
->pos
) > mp
->m_dirdatablk
)
116 * Precalculate offsets for . and .. as we will always need them.
118 * XXX(hch): the second argument is sometimes 0 and sometimes
121 dot_offset
= xfs_dir2_db_off_to_dataptr(mp
, mp
->m_dirdatablk
,
122 xfs_dir3_data_dot_offset(mp
));
123 dotdot_offset
= xfs_dir2_db_off_to_dataptr(mp
, mp
->m_dirdatablk
,
124 xfs_dir3_data_dotdot_offset(mp
));
127 * Put . entry unless we're starting past it.
129 if (ctx
->pos
<= dot_offset
) {
130 ctx
->pos
= dot_offset
& 0x7fffffff;
131 if (!dir_emit(ctx
, ".", 1, dp
->i_ino
, DT_DIR
))
136 * Put .. entry unless we're starting past it.
138 if (ctx
->pos
<= dotdot_offset
) {
139 ino
= xfs_dir2_sf_get_parent_ino(sfp
);
140 ctx
->pos
= dotdot_offset
& 0x7fffffff;
141 if (!dir_emit(ctx
, "..", 2, ino
, DT_DIR
))
146 * Loop while there are more entries and put'ing works.
148 sfep
= xfs_dir2_sf_firstentry(sfp
);
149 for (i
= 0; i
< sfp
->count
; i
++) {
152 off
= xfs_dir2_db_off_to_dataptr(mp
, mp
->m_dirdatablk
,
153 xfs_dir2_sf_get_offset(sfep
));
155 if (ctx
->pos
> off
) {
156 sfep
= xfs_dir3_sf_nextentry(mp
, sfp
, sfep
);
160 ino
= xfs_dir3_sfe_get_ino(mp
, sfp
, sfep
);
161 filetype
= xfs_dir3_sfe_get_ftype(mp
, sfp
, sfep
);
162 ctx
->pos
= off
& 0x7fffffff;
163 if (!dir_emit(ctx
, (char *)sfep
->name
, sfep
->namelen
, ino
,
164 xfs_dir3_get_dtype(mp
, filetype
)))
166 sfep
= xfs_dir3_sf_nextentry(mp
, sfp
, sfep
);
169 ctx
->pos
= xfs_dir2_db_off_to_dataptr(mp
, mp
->m_dirdatablk
+ 1, 0) &
175 * Readdir for block directories.
178 xfs_dir2_block_getdents(
179 xfs_inode_t
*dp
, /* incore inode */
180 struct dir_context
*ctx
)
182 xfs_dir2_data_hdr_t
*hdr
; /* block header */
183 struct xfs_buf
*bp
; /* buffer for block */
184 xfs_dir2_block_tail_t
*btp
; /* block tail */
185 xfs_dir2_data_entry_t
*dep
; /* block data entry */
186 xfs_dir2_data_unused_t
*dup
; /* block unused entry */
187 char *endptr
; /* end of the data entries */
188 int error
; /* error return value */
189 xfs_mount_t
*mp
; /* filesystem mount point */
190 char *ptr
; /* current data entry */
191 int wantoff
; /* starting block offset */
196 * If the block number in the offset is out of range, we're done.
198 if (xfs_dir2_dataptr_to_db(mp
, ctx
->pos
) > mp
->m_dirdatablk
)
201 error
= xfs_dir3_block_read(NULL
, dp
, &bp
);
206 * Extract the byte offset we start at from the seek pointer.
207 * We'll skip entries before this.
209 wantoff
= xfs_dir2_dataptr_to_off(mp
, ctx
->pos
);
211 xfs_dir3_data_check(dp
, bp
);
213 * Set up values for the loop.
215 btp
= xfs_dir2_block_tail_p(mp
, hdr
);
216 ptr
= (char *)xfs_dir3_data_entry_p(hdr
);
217 endptr
= (char *)xfs_dir2_block_leaf_p(btp
);
220 * Loop over the data portion of the block.
221 * Each object is a real entry (dep) or an unused one (dup).
223 while (ptr
< endptr
) {
226 dup
= (xfs_dir2_data_unused_t
*)ptr
;
230 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
231 ptr
+= be16_to_cpu(dup
->length
);
235 dep
= (xfs_dir2_data_entry_t
*)ptr
;
238 * Bump pointer for the next iteration.
240 ptr
+= xfs_dir3_data_entsize(mp
, dep
->namelen
);
242 * The entry is before the desired starting point, skip it.
244 if ((char *)dep
- (char *)hdr
< wantoff
)
247 cook
= xfs_dir2_db_off_to_dataptr(mp
, mp
->m_dirdatablk
,
248 (char *)dep
- (char *)hdr
);
250 ctx
->pos
= cook
& 0x7fffffff;
251 filetype
= xfs_dir3_dirent_get_ftype(mp
, dep
);
253 * If it didn't fit, set the final offset to here & return.
255 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
256 be64_to_cpu(dep
->inumber
),
257 xfs_dir3_get_dtype(mp
, filetype
))) {
258 xfs_trans_brelse(NULL
, bp
);
264 * Reached the end of the block.
265 * Set the offset to a non-existent block 1 and return.
267 ctx
->pos
= xfs_dir2_db_off_to_dataptr(mp
, mp
->m_dirdatablk
+ 1, 0) &
269 xfs_trans_brelse(NULL
, bp
);
273 struct xfs_dir2_leaf_map_info
{
274 xfs_extlen_t map_blocks
; /* number of fsbs in map */
275 xfs_dablk_t map_off
; /* last mapped file offset */
276 int map_size
; /* total entries in *map */
277 int map_valid
; /* valid entries in *map */
278 int nmap
; /* mappings to ask xfs_bmapi */
279 xfs_dir2_db_t curdb
; /* db for current block */
280 int ra_current
; /* number of read-ahead blks */
281 int ra_index
; /* *map index for read-ahead */
282 int ra_offset
; /* map entry offset for ra */
283 int ra_want
; /* readahead count wanted */
284 struct xfs_bmbt_irec map
[]; /* map vector for blocks */
288 xfs_dir2_leaf_readbuf(
289 struct xfs_inode
*dp
,
291 struct xfs_dir2_leaf_map_info
*mip
,
292 xfs_dir2_off_t
*curoff
,
293 struct xfs_buf
**bpp
)
295 struct xfs_mount
*mp
= dp
->i_mount
;
296 struct xfs_buf
*bp
= *bpp
;
297 struct xfs_bmbt_irec
*map
= mip
->map
;
298 struct blk_plug plug
;
305 * If we have a buffer, we need to release it and
306 * take it out of the mapping.
310 xfs_trans_brelse(NULL
, bp
);
312 mip
->map_blocks
-= mp
->m_dirblkfsbs
;
314 * Loop to get rid of the extents for the
317 for (i
= mp
->m_dirblkfsbs
; i
> 0; ) {
318 j
= min_t(int, map
->br_blockcount
, i
);
319 map
->br_blockcount
-= j
;
320 map
->br_startblock
+= j
;
321 map
->br_startoff
+= j
;
323 * If mapping is done, pitch it from
326 if (!map
->br_blockcount
&& --mip
->map_valid
)
327 memmove(&map
[0], &map
[1],
328 sizeof(map
[0]) * mip
->map_valid
);
334 * Recalculate the readahead blocks wanted.
336 mip
->ra_want
= howmany(bufsize
+ mp
->m_dirblksize
,
337 mp
->m_sb
.sb_blocksize
) - 1;
338 ASSERT(mip
->ra_want
>= 0);
341 * If we don't have as many as we want, and we haven't
342 * run out of data blocks, get some more mappings.
344 if (1 + mip
->ra_want
> mip
->map_blocks
&&
345 mip
->map_off
< xfs_dir2_byte_to_da(mp
, XFS_DIR2_LEAF_OFFSET
)) {
347 * Get more bmaps, fill in after the ones
348 * we already have in the table.
350 mip
->nmap
= mip
->map_size
- mip
->map_valid
;
351 error
= xfs_bmapi_read(dp
, mip
->map_off
,
352 xfs_dir2_byte_to_da(mp
, XFS_DIR2_LEAF_OFFSET
) -
354 &map
[mip
->map_valid
], &mip
->nmap
, 0);
357 * Don't know if we should ignore this or try to return an
358 * error. The trouble with returning errors is that readdir
359 * will just stop without actually passing the error through.
365 * If we got all the mappings we asked for, set the final map
366 * offset based on the last bmap value received. Otherwise,
367 * we've reached the end.
369 if (mip
->nmap
== mip
->map_size
- mip
->map_valid
) {
370 i
= mip
->map_valid
+ mip
->nmap
- 1;
371 mip
->map_off
= map
[i
].br_startoff
+ map
[i
].br_blockcount
;
373 mip
->map_off
= xfs_dir2_byte_to_da(mp
,
374 XFS_DIR2_LEAF_OFFSET
);
377 * Look for holes in the mapping, and eliminate them. Count up
380 for (i
= mip
->map_valid
; i
< mip
->map_valid
+ mip
->nmap
; ) {
381 if (map
[i
].br_startblock
== HOLESTARTBLOCK
) {
383 length
= mip
->map_valid
+ mip
->nmap
- i
;
385 memmove(&map
[i
], &map
[i
+ 1],
386 sizeof(map
[i
]) * length
);
388 mip
->map_blocks
+= map
[i
].br_blockcount
;
392 mip
->map_valid
+= mip
->nmap
;
396 * No valid mappings, so no more data blocks.
398 if (!mip
->map_valid
) {
399 *curoff
= xfs_dir2_da_to_byte(mp
, mip
->map_off
);
404 * Read the directory block starting at the first mapping.
406 mip
->curdb
= xfs_dir2_da_to_db(mp
, map
->br_startoff
);
407 error
= xfs_dir3_data_read(NULL
, dp
, map
->br_startoff
,
408 map
->br_blockcount
>= mp
->m_dirblkfsbs
?
409 XFS_FSB_TO_DADDR(mp
, map
->br_startblock
) : -1, &bp
);
412 * Should just skip over the data block instead of giving up.
418 * Adjust the current amount of read-ahead: we just read a block that
422 mip
->ra_current
-= mp
->m_dirblkfsbs
;
425 * Do we need more readahead?
427 blk_start_plug(&plug
);
428 for (mip
->ra_index
= mip
->ra_offset
= i
= 0;
429 mip
->ra_want
> mip
->ra_current
&& i
< mip
->map_blocks
;
430 i
+= mp
->m_dirblkfsbs
) {
431 ASSERT(mip
->ra_index
< mip
->map_valid
);
433 * Read-ahead a contiguous directory block.
435 if (i
> mip
->ra_current
&&
436 map
[mip
->ra_index
].br_blockcount
>= mp
->m_dirblkfsbs
) {
437 xfs_dir3_data_readahead(NULL
, dp
,
438 map
[mip
->ra_index
].br_startoff
+ mip
->ra_offset
,
440 map
[mip
->ra_index
].br_startblock
+
446 * Read-ahead a non-contiguous directory block. This doesn't
447 * use our mapping, but this is a very rare case.
449 else if (i
> mip
->ra_current
) {
450 xfs_dir3_data_readahead(NULL
, dp
,
451 map
[mip
->ra_index
].br_startoff
+
457 * Advance offset through the mapping table.
459 for (j
= 0; j
< mp
->m_dirblkfsbs
; j
++) {
461 * The rest of this extent but not more than a dir
464 length
= min_t(int, mp
->m_dirblkfsbs
,
465 map
[mip
->ra_index
].br_blockcount
-
468 mip
->ra_offset
+= length
;
471 * Advance to the next mapping if this one is used up.
473 if (mip
->ra_offset
== map
[mip
->ra_index
].br_blockcount
) {
479 blk_finish_plug(&plug
);
487 * Getdents (readdir) for leaf and node directories.
488 * This reads the data blocks only, so is the same for both forms.
491 xfs_dir2_leaf_getdents(
492 xfs_inode_t
*dp
, /* incore directory inode */
493 struct dir_context
*ctx
,
496 struct xfs_buf
*bp
= NULL
; /* data block buffer */
497 xfs_dir2_data_hdr_t
*hdr
; /* data block header */
498 xfs_dir2_data_entry_t
*dep
; /* data entry */
499 xfs_dir2_data_unused_t
*dup
; /* unused entry */
500 int error
= 0; /* error return value */
501 int length
; /* temporary length value */
502 xfs_mount_t
*mp
; /* filesystem mount point */
503 int byteoff
; /* offset in current block */
504 xfs_dir2_off_t curoff
; /* current overall offset */
505 xfs_dir2_off_t newoff
; /* new curoff after new blk */
506 char *ptr
= NULL
; /* pointer to current data */
507 struct xfs_dir2_leaf_map_info
*map_info
;
510 * If the offset is at or past the largest allowed value,
511 * give up right away.
513 if (ctx
->pos
>= XFS_DIR2_MAX_DATAPTR
)
519 * Set up to bmap a number of blocks based on the caller's
520 * buffer size, the directory block size, and the filesystem
523 length
= howmany(bufsize
+ mp
->m_dirblksize
,
524 mp
->m_sb
.sb_blocksize
);
525 map_info
= kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info
, map
) +
526 (length
* sizeof(struct xfs_bmbt_irec
)),
528 map_info
->map_size
= length
;
531 * Inside the loop we keep the main offset value as a byte offset
532 * in the directory file.
534 curoff
= xfs_dir2_dataptr_to_byte(mp
, ctx
->pos
);
537 * Force this conversion through db so we truncate the offset
538 * down to get the start of the data block.
540 map_info
->map_off
= xfs_dir2_db_to_da(mp
,
541 xfs_dir2_byte_to_db(mp
, curoff
));
544 * Loop over directory entries until we reach the end offset.
545 * Get more blocks and readahead as necessary.
547 while (curoff
< XFS_DIR2_LEAF_OFFSET
) {
551 * If we have no buffer, or we're off the end of the
552 * current buffer, need to get another one.
554 if (!bp
|| ptr
>= (char *)bp
->b_addr
+ mp
->m_dirblksize
) {
556 error
= xfs_dir2_leaf_readbuf(dp
, bufsize
, map_info
,
558 if (error
|| !map_info
->map_valid
)
562 * Having done a read, we need to set a new offset.
564 newoff
= xfs_dir2_db_off_to_byte(mp
, map_info
->curdb
, 0);
566 * Start of the current block.
571 * Make sure we're in the right block.
573 else if (curoff
> newoff
)
574 ASSERT(xfs_dir2_byte_to_db(mp
, curoff
) ==
577 xfs_dir3_data_check(dp
, bp
);
579 * Find our position in the block.
581 ptr
= (char *)xfs_dir3_data_entry_p(hdr
);
582 byteoff
= xfs_dir2_byte_to_off(mp
, curoff
);
584 * Skip past the header.
587 curoff
+= xfs_dir3_data_entry_offset(hdr
);
589 * Skip past entries until we reach our offset.
592 while ((char *)ptr
- (char *)hdr
< byteoff
) {
593 dup
= (xfs_dir2_data_unused_t
*)ptr
;
595 if (be16_to_cpu(dup
->freetag
)
596 == XFS_DIR2_DATA_FREE_TAG
) {
598 length
= be16_to_cpu(dup
->length
);
602 dep
= (xfs_dir2_data_entry_t
*)ptr
;
604 xfs_dir3_data_entsize(mp
, dep
->namelen
);
608 * Now set our real offset.
611 xfs_dir2_db_off_to_byte(mp
,
612 xfs_dir2_byte_to_db(mp
, curoff
),
613 (char *)ptr
- (char *)hdr
);
614 if (ptr
>= (char *)hdr
+ mp
->m_dirblksize
) {
620 * We have a pointer to an entry.
623 dup
= (xfs_dir2_data_unused_t
*)ptr
;
625 * No, it's unused, skip over it.
627 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
628 length
= be16_to_cpu(dup
->length
);
634 dep
= (xfs_dir2_data_entry_t
*)ptr
;
635 length
= xfs_dir3_data_entsize(mp
, dep
->namelen
);
636 filetype
= xfs_dir3_dirent_get_ftype(mp
, dep
);
638 ctx
->pos
= xfs_dir2_byte_to_dataptr(mp
, curoff
) & 0x7fffffff;
639 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
640 be64_to_cpu(dep
->inumber
),
641 xfs_dir3_get_dtype(mp
, filetype
)))
645 * Advance to next entry in the block.
649 /* bufsize may have just been a guess; don't go negative */
650 bufsize
= bufsize
> length
? bufsize
- length
: 0;
654 * All done. Set output offset value to current offset.
656 if (curoff
> xfs_dir2_dataptr_to_byte(mp
, XFS_DIR2_MAX_DATAPTR
))
657 ctx
->pos
= XFS_DIR2_MAX_DATAPTR
& 0x7fffffff;
659 ctx
->pos
= xfs_dir2_byte_to_dataptr(mp
, curoff
) & 0x7fffffff;
662 xfs_trans_brelse(NULL
, bp
);
672 struct dir_context
*ctx
,
675 int rval
; /* return value */
676 int v
; /* type-checking value */
678 trace_xfs_readdir(dp
);
680 if (XFS_FORCED_SHUTDOWN(dp
->i_mount
))
681 return XFS_ERROR(EIO
);
683 ASSERT(S_ISDIR(dp
->i_d
.di_mode
));
684 XFS_STATS_INC(xs_dir_getdents
);
686 if (dp
->i_d
.di_format
== XFS_DINODE_FMT_LOCAL
)
687 rval
= xfs_dir2_sf_getdents(dp
, ctx
);
688 else if ((rval
= xfs_dir2_isblock(NULL
, dp
, &v
)))
691 rval
= xfs_dir2_block_getdents(dp
, ctx
);
693 rval
= xfs_dir2_leaf_getdents(dp
, ctx
, bufsize
);